EMI explained with an amortisation table: why early payments are mostly interest

The formula

EMI = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where P is the principal, r is the monthly interest rate (annual rate ÷ 12 ÷ 100) and n is the number of monthly payments.

For 1,000,000 at 12% per year over 5 years: r = 0.01, n = 60, (1.01)⁶⁰ = 1.8167. EMI = 1,000,000 × 0.01 × 1.8167 ÷ 0.8167 = 22,244.45 per month. Over 60 months you pay 1,334,667, so total interest is 334,667 — about a third of the amount borrowed.

Month by month

Each month, interest is charged on the outstanding balance. In month one that is 1,000,000 × 1% = 10,000, so only 12,244 of the 22,244 EMI reduces the loan. As the balance falls, the interest portion shrinks and the principal portion grows. By the final month the interest is a few hundred and almost the whole EMI clears the remaining balance.

Why tenure matters more than the rate you negotiate

Borrowers often fight for a 0.25% rate reduction while accepting a longer tenure to make the EMI feel affordable. The table shows the cost of that trade: stretching the same 12% loan from 5 to 10 years cuts the EMI by about 35% but more than doubles the interest paid.

Prepayment: why paying early is powerful

Because interest is charged on the balance, any extra payment in the early years removes principal that would otherwise attract interest for the whole remaining term. Paying one extra EMI (22,244) at month 12 of the 5-year loan above saves roughly 13,000–14,000 in interest if the tenure is shortened; the same extra payment at month 48 saves under 3,000. Check whether your lender charges a prepayment penalty and whether they shorten the tenure or reduce the EMI — shortening the tenure saves far more.

Flat rate vs. reducing balance

Some lenders quote a “flat” rate where interest is charged on the original principal for the whole term. A 7% flat rate on a 5-year loan is roughly equivalent to a 12–13% reducing-balance rate — the number CalculatorCamp’s EMI calculator uses. Always ask which method a quote uses before comparing offers.

Reading a loan quote: rate, APR and fees

The headline interest rate is not the whole cost. Processing fees, documentation charges, mandatory insurance and late-payment penalties all add to what you pay. Regulators in many countries require lenders to publish an annual percentage rate (APR) that folds the compulsory fees into a single comparable number; where an APR is given, compare that rather than the nominal rate.

A quick self-check: a 2% processing fee on the 1,000,000 loan above is 20,000 up front — equivalent to raising the interest rate by roughly 0.9 percentage points over five years. Two offers at 12.0% with a 2% fee and 12.9% with no fee cost almost exactly the same.

Fixed vs. floating rate

A fixed-rate EMI never changes, so budgeting is simple but you pay a premium for certainty. A floating (variable) rate tracks a benchmark; when it moves, lenders usually keep the EMI constant and change the tenure instead, which is easy to miss. After a rate rise, ask for a fresh amortisation schedule and check the new end date. If it has stretched by a year, consider a one-off prepayment or an EMI increase to pull it back.

Checklist before you sign

• Ask for the full amortisation schedule, not just the EMI.
• Confirm whether the rate is flat or reducing balance, fixed or floating.
• Add all compulsory fees to the interest total before comparing lenders.
• Check the prepayment rules: penalty percentage, minimum amount, tenure vs EMI reduction.
• Keep the EMI under about 35–40% of take-home pay so a rate rise stays affordable.